zeichenkopf for machines, reissbretter, zeichenplatten and dgl

摘要

The small sized drawing board has the drawing rail, pref. of triangular shape, aligned by means of ridges or grooves at the edges. The rail is for drawing lines or alignment of other drawing devices, especially triangles, adjustable drawing heads with square rules or writing or drawing patterns. The straight edge is pivoted on a swivel head, and has a knob to pull this down into a conical socket to lock up the assembly. The knob may be internally threaded onto a vertically screw.